1. Field of the Invention
The present invention is related to a control device for a memory, and more particularly, to a control device and control method with programmable memory protocol for elastically controlling memories from various suppliers.
2. Description of the Related Art
In various storage media, the use of pen drives is increasingly popular since they have features of small volume, big capacity, and convenience. Generally, the pen drive uses a nonvolatile memory, such as flash memory, as a storage unit. Manufacturers control the flash memories with appropriate memory protocols according to the flash memories from various suppliers.
The memory protocol means transmitting a command corresponding to the operations, such as data reading, writing, or erasing, defined by the memory suppliers to a given memory address. The memory protocols in general are implemented in software and hardware. For software, the micro controller unit (MCU) communicates with the flash memory via a memory interface, and each command is given by the MCU. In addition to increasing power consumption of the MCU, the entire working performance is reduced due to the MCU needs several cycles to execute each command.
For hardware, the MCU and some logic control circuitries communicate with the flash memory via the memory interface, and these logic control circuitries are, for example, state machine circuitries. However, because not all the commands or the ways of giving the commands to operate the flash memories from various suppliers are the same, for instance, a supplier may add operations and commands which other suppliers do not include to speed up reading and writing, the design of logic control circuitries have to be changed to meet the requirements of various suppliers. Therefore, logic gate counts need to be increased for the memory protocol, and the design lacks flexibility.